It's rare any of us can say "for sure" when discussing how substances affect us -- however it's 100% that licorice reduced my cortisol highs. And, as I said, by reducing those over abundance highs, it meant I didn't crash (as badly). So it didn't destory the cortisol, it seems to have put it back into storage so I could use it later in a normal way.
It did the same for others that I know of personally. I understand it doesn't work 100% for everyone.
Licorice tea I use occasionally now when I'm a bit jacked, and it's great.